The present invention relates generally to an electronic apparatus such as a book-type portable computer, and more particularly to a structure for connecting a cable to a circuit board contained within a housing body of the apparatus.
A book-type portable computer comprises a main body unit having a keyboard, and a display unit supported on the main body unit. The main body unit has a box-shaped housing body. The housing body comprises a lower housing and an upper housing detachably coupled to the lower housing. The lower housing has a bottom wall and peripheral walls extending upward from peripheral edge portions of the bottom wall. The upper housing has a top wall on which the keyboard is mounted. The top wall is continuous with upper end portions of the peripheral walls and is opposed to the bottom wall. A circuit board is contained within the housing body. A number of IC chips and connectors are mounted on the circuit board. The circuit board is supported on the bottom wall of the lower housing.
The display unit comprises a display housing having a flat box shape, and a liquid crystal display (LCD) contained within the display housing. The display housing has leg portions extending toward the top wall of the upper housing. The leg portions are rotatably supported on a rear end portion of the housing body by means of hinge devices.
In this type of portable computer, the circuit board and the LCD are electrically connected to each other over a cable. The cable comprises a great number of lead lines. The cable has a first end portion with a first relay connector and a second end portion with a second relay connector. The first relay connector is connected to a connector of the circuit board, and the second relay connector is connected to a driver circuit of the LCD. The cable is guided into the housing body from the inside of the display housing through the leg portions.
The portable computer, wherein the connecting portion between the first relay connector of the cable and the connector of the circuit board is situated below the keyboard, has an opening portion for exposing the connector of the circuit board. The opening portion is formed in the top wall of the upper housing and is covered by the keyboard. Accordingly, after the upper housing is coupled to the lower housing, the first relay connector of the cable is connected to the connection on the circuit board through the opening portion of the upper housing. After the first relay connector is connected to the connector, the keyboard is mounted on the top wall.
In the case of a portable computer wherein the connecting portion between the first relay connector of the cable and the connector on the circuit board is situated in rear of the keyboard, this connecting portion is covered by the top wall of the upper housing. Thus, a first end portion of the cable is drawn out in advance to the lower side of the upper housing. The first relay connector continuous with the first end portion is connected to the connector on the circuit board before the upper housing is coupled to the lower housing.
In a conventional portable computer, the cable is passed through the coupling portion between the leg portions of the display housing and the housing body. The cable is thus guided into the housing body from a location behind the keyboard. As a result, in the case of the portable computer wherein the connecting portion between the first relay connector of the cable and the connector of the circuit board is situated below the keyboard, the cable guided to the rear end portion of the housing body needs to be drawn toward the front side of the housing body. Consequently, the cable extends over the circuit board and the length of the cable running within the housing body increases.
In addition, since high-speed signals flow through the cable, electromagnetic noise may be induced or coupled between the cable and the circuit pattern or circuit element on the circuit board. It is also possible that the cable itself may function as an antenna radiating noise. Thus, the noise radiated from the inside of the housing body increases, and electromagnetic shielding for the housing body needs to be strengthened.
Furthermore, since the cable extends from the rear end portion of the housing body toward the region below the keyboard, a space for passing the cable needs to be provided within the housing body. It is time-consuming to determine the arrangement of structural parts within the housing body and to connect the cable.
In the case of the portable computer wherein the connecting portion between the first relay connector of the cable and the connector on the circuit board is situated in rear of the keyboard, this connecting portion is covered by the top wall of the upper housing. It is thus necessary to connect the first relay connector to the connector on the circuit board in the state in which the upper housing is lifted up from the lower housing and the circuit board is exposed to the outside of the lower housing. In order to facilitate this connecting work, it is necessary to prepare a relatively long cable, and accordingly, the length of the cable running within the housing body increases. Such a cable may function as an antenna radiating noise. In addition, there is a need to provide a special space within the housing body in order to situate the cable. Because of these problems, it is difficult to reduce the size of the housing body.